By utilizing the space resources of the highway itself, and replacing the sound barriers that would otherwise need to be installed, photovoltaic sound barriers absorb noise and also generate clean energy, providing distributed power generation for streetlights on the highway.
1. Global Application Cases of Photovoltaic Sound Barriers
In 2015, the Suzhou West Ring Elevated Road adopted double-sided, double-glass photovoltaic modules as road noise barriers. The Suzhou Municipal Administration provided a one-kilometer section of the West Ring Elevated Road as a pilot section for the solar sound barrier, allowing photovoltaic companies to invest in its construction. Six years later, Jiangsu Yuzhao Energy Technology, the company that initially supplied the photovoltaic modules for the noise barriers, has long since disappeared.
Prior to this, Switzerland had installed the world's first photovoltaic sound barrier in 1989, with a capacity of 100 kW and a length of less than 1 kilometer. However, to be precise, this sound barrier was more like a pure photovoltaic array, and the system is still in operation more than 20 years later.
Subsequently, in 2007, Seoul, South Korea, installed the country's first photovoltaic soundproof wall with a capacity of 30KW. Its integrated design and modular installation resulted in an aesthetically pleasing, time-saving, and labor-saving solution.
Germany also installed a 7.544MW photovoltaic sound barrier in Munich in 2013.
In 2012, my country's Jiasheng Optoelectronics (a subsidiary of Yingli) also developed a 90KW photovoltaic sound barrier, which features lightweight and high efficiency, bifacial power generation, vertical installation, and self-cleaning function.
Selection of photovoltaic noise barriers
Photovoltaic noise barriers need to have two functions: sound insulation and power generation, with sound insulation being the most important and a basic requirement for highway barriers.
Because photovoltaic (PV) noise barriers are installed vertically, both sides can be exposed to sunlight at different times of day. Even when facing away from the sun, the reflected light from the environment is superior to that of common double-sided power generation ground surfaces. Therefore, most PV noise barrier modules are designed with double-sided power generation capabilities.
Before 2015, the cost of bifacial power generation was still relatively high. Now, bifacial batteries are cheaper than single-sided batteries. Photovoltaic sound barriers are also recommended as a smart transportation energy solution, and are attracting attention in various scenarios such as subways, elevated roads, and highways.
Photovoltaic modules include bifacial crystalline silicon, single-sided crystalline silicon, and thin-film photovoltaics. So, which type of photovoltaic power generation module should be chosen for a photovoltaic sound barrier?
Belgium is conducting such selection tests.
Photovoltaic noise barrier test site
A Belgian company is building two photovoltaic noise barrier testing facilities to evaluate different photovoltaic technologies that can achieve sound insulation while reducing costs and maximizing power generation revenue.
Planning large-scale projects in Belgium is nearly impossible due to land and policy restrictions, making the construction of ground-mounted photovoltaic power plants nearly impossible. A joint laboratory called EngyValw, established between the Belgian research institute Ku-Luuvin Vito, IMEC, and Haselt University, is testing the functionality of photovoltaic noise barriers.
One of the two installations under construction is 13 meters wide and 5 meters high, facing south, and is equipped with solar panels using three different battery technologies: monocrystalline bifacial PERC panels, cadmium telluride thin-film solar panels, and CIGS solar modules supplied by TNO/Solliance of the Netherlands. All modules are equipped with inverters and power optimizers.
IMEC has developed a power generation assessment model to statistically analyze the impact of cloud cover, sunlight angle, and frequent traffic on power generation data, and to record the power generation efficiency and stability data of solar modules. The model will also monitor and record the noise isolation effectiveness of different modules.
The research team will also build 68 solar-powered sound barriers in the Netherlands, with the test device measuring 12 meters wide. To further improve noise reduction, transparent sound-absorbing materials may be placed on the surface of the solar panels, but the currently used sound-absorbing materials result in a 30% loss of power generation.
Through field research, scientists need to prove whether solar-powered sound barriers are effective in high-noise environments such as highways and railways.
